The Experimental and Numerical Analysis of the Joining Processes for Air Conditioning Systems
In the paper the results of welding of car’s air-conditioning elements are presented. These systems based on, mainly, the environmental unfriendly refrigerants. Thus, the producers of cars will have to stop using traditional refrigerant and to change it to carbon dioxide (R744). This refrigerant is environmental friendly. However, it should be noted that the air condition system working with R744 refrigerant operates at high temperature (up to 150 °C) and high pressure (up to 130 bar). These two parameters are much higher than for other refrigerants. Thus new materials, design as well as joining technologies are strongly needed for these systems. AISI 304 and 316L steels as well as aluminium alloys 5xxx are ranked among the prospective materials. As a joining process laser welding, plasma welding, electron beam welding as well as high rotary friction welding can be applied. In the study, the metallographic examination based on light microscopy as well as SEM was applied to estimate the quality of welded joints. The analysis of welding was supported by numerical modelling based on Sysweld software. The results indicated that using laser, plasma and electron beam welding, it is possible to obtain proper quality of welds in stainless steel. Moreover, high rotary friction welding allows to guarantee the metallic continuity in the aluminium welded area. The metallographic examination revealed that the grain growth in the heat affected zone (HAZ) in laser and electron beam welded joints were not observed. It is due to low heat input and short welding time. The grain growth and subgrains can be observed at room temperature when the solidification mode is austenitic. This caused low microstructural changes during solidification. The columnar grain structure was found in the weld metal. Meanwhile, the equiaxed grains were detected in the interface. The numerical modelling of laser welding process allowed to estimate the temperature profile in the welded joint as well as predicts the dimensions of welds. The agreement between FEM analysis and experimental data was achieved.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.2571833Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 709
 Janotkova, M. Pavelek, New Trends in the Field of Automobile Air Conditioning. https://www.aiha.org/aihce06/handouts/janotkova.pdf (Created 2006.05.03).
 Arizone, Automotive Air Conditioning Training Manual http://www.ariazone.com.mk/pdf/Automotive%20Air%20Conditioning%20Training%20Manual.pdf (Created 2007.06.02).
 Natural refrigerants – CO2-based air conditioning system put to practical testing. http://www.umweltbundesamt.de/sites/default/files/medien/publikation/long/3654.pdf (Created 2009.06.08).
 Directive 2006/40/EC of the European Parliament and of the Council of 17 May 2006 relating to emissions from air-conditioning systems in motor vehicles and amending Council Directive 70/156/EEC
 M. Mohanraj, S. Jayaraj, C. Muraleedharan, “Environment friendly alternatives to halogenated refrigerants—A review”. International Journal of Greenhouse Gasses Control, vol. 3, pp. 108-119, 2009.
 K.S. Prasad, Ch. Rao, D.N. Rao, “A review on welding of AISI 304L austenitic stainless steel”, J. Manuf. Sci. Prod., vol. 14, pp. 1-11, 2014.
 M.St. Weglowski, S. Stano, G. Michta, et al., “Structural characterization of Nd:YAG laser welded joint of dual phase steel”. Archives of Metallurgy and Materials, vol. 55, pp. 211-220, 2010.
 E. Taban, A. Dhooge, E. Kaluc, “Plasma Arc Welding of Modified 12% Cr Stainless Steel”, Materials and Manufacturing Processes, vol. 24, pp. 649-656, 2009.
 M.St. Węglowski, S. Błacha, A. Philips, Electron beam welding – Techniques and trends – Review, Vacuum, vol. 130, pp. 72-92, 2016.
 S.A.A.A Mousavi, A. Gharedaghi, et al., “Metallurgical investigations of laser welding of AISI 304 stainless steel”. Materials Science Forum, vol. 580-582, pp. 41-44, 2008.
 S.P. Rajan, S.S. Kumaran, “Friction welding of 304 austenitic stainless steel tube to tube plate joints using external tool”. Journal of Advanced Mechanical Design, Systems, and Manufacturing, vol. 9, pp. 1-8, 2015.
 R. Blondeau, Metallurgy and Mechanics of Welding Processes and Industrial Applications, ISTE Ltd and John Wiley & Sons, Inc., (2008). p. 419.
 S. Saha, M. Mukherjee, T.K. Pal, “Microstructure, texture, and mechanical property analysis of Gas Metal Arc welded AISI 304 austenitic stainless steel”. Journal of Materials Engineering and Performance, vol. 24, pp. 1125-1139, 2015.
 Melting temperature ranges for stainless steels, www.bssa.org.uk/topics.php?article=103, accessed on 28.09.2016.